The present invention relates in general to an apparatus and associated method for the detection of cancerous tumors. More particularly, the invention relates to a system for the screening of cancerous tumors particularly female breast tumors. Even more particularly, the present invention relates to a microwave system for breast screening for locating tumors.
There is a continuing need for providing a reliable, noninvasive and nonhazardous technique for the detection of cancerous tumors especially breast tumors. One such technique is an infrared thermographic technique for cancer tumor detection, based on elevated temperatures often found in malignant tumors. This technique is noninvasive and nonhazardous but is of questionable accuracy. A more accurate techinque is mammography. One objection to the well known mammography technique is that it exposes the person to hazardous x-rays. With regard to infrared thermography, one of its drawbacks is its poor penetration through biological tissues, resulting in the measurement of only surface temperature.
Reference is also made to my U.S. Pat. No. 4,346,716 covering a microwave detection system for detection of cancerous tumors. This system employs a single detection antenna. If this system is employed for breast screening the examination time is far too long and is thus unacceptable. Furthermore, even though microwave techniques provide subsurface sensing, there is some limitation on the limit of depth detection.
In one prior system employing a single antenna this had to be mechanically positioned requiring approximately 1.5 minutes per site and a minimum of 9 positions per breast in order to provide acceptable coverage. This resulted in a time of examination of 30-40 minutes. Again, this is too long a period of time for practical purposes.
A further problem realized with the single antenna system is associated with the depth of the tumor, particularly in large breasts. It was found that there was a resultant high number of particularly false negative readings.
Accordingly, it is an object of the present invention to provide an improved method and apparatus for the detection of cancerous tumors, particularly breast tumors.
Another object of the present invention is to provide an improved breast screening technique employing microwave detection principles.
A further object of the present invention is to provide an improved microwave breast screening system employing multiple antennae which is instrumental in dramatically reducing the examination time.
Still another object of the presesnt invention is to provide an improved microwave breast screening system in which all antennae are stabilized at the same time eliminating thermal drift due to both patient and environmental changes.
A further object of the present invention is to provide a microwave breast screening system used in combination with breast compression so as to permit examination from opposite surfaces of the compressed breast tissue.
Still a further object of the present invention is to provide a microwave breast screening system having multiple antennae in which any given antenna thereof may be optimized for a given site. For example, the match of the nipple area of the breast is different from the surrounding tissue and thus the antenna element associated therewith can be optimized as to impedance match for that particular site.